Mac OS X Public Beta
Mac OS X Public Beta is a version of Mac OS X, released on September 13, 2000. The "PB" as it was known marked the first public availability of the Aqua interface and Apple made many changes to the UI based on customer feedback. Mac OS X Public Beta expired and ceased to function in Spring 2001. However, via some commands in OpenFirmware on G3 and G4 Macs, the system clock can be altered, allowing the use of it even after Spring 2001. (Intel-based Macs do not have OpenFirmware, nor can they run classic versions of OS X, which were compiled for the PPC platform).
One of the ways that the Public Beta can be distinguished from the gold 10.0 release is the fact that the Apple logo was placed in the center of the Menubar, and was a non-functional decoration. The Desktop menu also appeared in the Public Beta.